


The Diagonal of the Square

by thedeathchamber



Category: Sherlock (TV)
Genre: Backstory, Emotional Hurt/Comfort, Friendship/Love, Gen, Holmes Brothers, M/M, Mental Health Issues, Pre-Canon, Suicide Attempt
Language: English
Status: Completed
Published: 2014-02-02
Updated: 2014-02-02
Packaged: 2018-01-10 23:20:46
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,002
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1165794
Author URL: https://archiveofourown.org/users/thedeathchamber/pseuds/thedeathchamber
Summary: <blockquote class="userstuff">
              <p>“Well, this is a surprise.” Mycroft answered after the third dial tone; Sherlock’s thumb slid briefly over the end call button. “What can I do for you, brother dear?” </p><p>Pre-Reichenbach Fall. No spoilers for season 3 (though it was inspired by 'The Sign of Three').</p>
            </blockquote>





	The Diagonal of the Square

_[...] it is a lifelong fight to keep from sinking._

    -Elizabeth Wurtzel, _Prozac Nation_

* * *

Mycroft touched the back of his knuckles to the door before pushing it open. Sherlock was curled up on the window seat wrapped in a duvet, though his bare toes peeked out at the bottom.The smudged outline of his profile revealed nothing, but the dim light coming in from the window betrayed a nervous twitch of his fingers and tension in the rigid line of his neck and shoulders. 

“Ghastly habit, Sherlock.” Mycroft said, wrinkling his nose. 

“Which one?” Sherlock drawled, turning his face away from the light spilling in from the hallway. 

“Shall I expect another call from Mummy that you nearly burned down the house again?”  Mycroft asked, closing the door behind him.

“It was a contained fire.” Sherlock protested lazily. “For an experiment.” 

“I’m sure.” Mycroft sat at the foot of the bed, hands folded on his knee. “I cannot approve of the blackmailing either, you understand. Poor Gavin has been in the family since before you were born.”

Sherlock shrugged. “It’s not blackmail. It’s a mutually beneficial arrangement.”

“I hardly think so.” Mycroft replied. “If you do not put an end to it--” 

Sherlock stiffened and turned his head to look at him searchingly. Mycroft raised his eyebrows. “--I will.” 

“What are you going to do?” Sherlock said scornfully. “I’m not falling for your empty threats again.”

“I’ll tell Mummy, of course.” Mycroft said.

“Well, _I_ ’ll tell her I only started because _you_ were doing it.” Sherlock cut him off. 

Mycroft could not hold in a tired exhalation. “A necessary evil, but I expect she might keep a closer eye on you at the very least.” 

Sherlock eyed Mycroft with disdain. ““Mummy’s been busy planning your big event. Can’t expect her to do everything.”

“That is true.” Mycroft conceded. “And I should have anticipated something of this sort might happen. ”

The noise from the party downstairs seemed momentarily loud: discordant music and unintelligible conversation. Three distinct ticks of the clock in the hallway. “Nothing happened.”

“Indeed. A simple misjudgement on my behalf and a slight miscalculation on your end. Is that our definitive account of the... incident?”

Sherlock’s tremulous intake of breath was audible. “What do you want, Mycroft?”

“You wanted to see me, I believe.”

Sherlock glared at Mycroft. “I wanted to see you three days ago, not anymore.”

“I was busy, Sherlock. A previous engagement of the utmost importance, I’m afraid.” Mycroft explained, lowering his eyes to fiddle with a loose button on his vest. 

Sherlock lips tightened. “Yes, your roommate was quite clear on that point. He wouldn’t even let me into the room.” 

Mycroft smoothed a hand idly over the coverlet. “You have to make allowances for David’s mistrust. After all, the last time you came to see me you _appropriated_ several of his belongings--”

“This was an _emergency_.” Sherlock interrupted sharply. 

“--and the emergency then turned out to be nothing more than you being _unbearably_ bored.” 

Sherlock made a rude, inarticulate sound.

“You could have left a message.” Mycroft said, voice low and hoarse, after a moment. “Instead you came back here and...” He managed a deep breath and continued. “...went to sleep.”

“Isn’t that what people do? _Sleep_ to for _get_ and all that.” Sherlock replied to the ceiling. 

“Hm. Yes. Though I believe most people aim for a seven to nine hour sleep.” Mycroft smiled thinly. “Whereas you were going for something more _permanent_.”

“I don’t know what you’re talking about.” Sherlock answered tonelessly. 

“Mummy said you’d taken ill.” Mycroft continued. “Ginger tea and crackers are not quite as effective as an antiemetic drug, I fear, little brother.” 

“Well, now you know what to get me for Christmas.” Sherlock retorted, throwing off the duvet violently and lurching to his feet. 

“Don’t be absurd.” Mycroft snapped. 

Sherlock pushed the stack of books and the glass cup on the chest of drawers to the floor. 

‘Stop that. Someone will hear and come up.” 

He grabbed a cushion from the window seat and threw it at Mycroft with a snarl. “You should go back to the party. Why are you even here? I’m sure _someone_ will eventually begin to wonder where you’ve disappeared to.”

“I would have come, Sherlock.” Mycroft let out. He gripped the cushion in a white-knuckled grip. “If you’d called. If you’d left a message. I would have come.” 

Sherlock stared at Mycroft in silence. “I’m not quite omniscient yet.” Mycroft sighed.

“Yet.” Sherlock muttered. He wrenched the cushion from his brother’s grip and sat back down, hugging it to his chest. 

“Indeed.” Mycroft slid to the corner of the bed closer to Sherlock. “This whole business with that boy is most regrettable.”

Sherlock kept his eyes averted. “I thought-- I thought he was my _friend_.” 

“I know.” Mycroft said gently. ”Unfortunately, life is full of disappointments, little brother.” 

“I’m well aware of that.” Sherlock interjected.

“I did warn you not to get involved.” Mycroft continued with strained delicacy. “All this _unpleasantness_ could have been avoided.”

“Ah. Yes, _thank you_ , Mycroft _._ I should have known you’d go to all this trouble just to say ‘I told you so.’” Sherlock let the cushion drop to the floor and dragging the duvet over himself, curled up in the seat with his back turned to his brother. “Go away.”

“ _Sherlock._ ” Mycroft bent to retrieve the cushion from the floor and put it on the bed next to him. 

Sherlock pulled the duvet nearly over his head. 

Mycroft contemplated his brother in silence, steepled fingers pressed against his lips. “I trust there will be no more such instances of lack of judgement on your part.”

Sherlock mumbled in answer to the hint of a question in his tone. 

“I didn’t catch that.”

“I said I’ll be sure to think things through more carefully next time.” Sherlock repeated viciously. 

Mycroft ran his fingers through his hair in a rare nervous gesture. “For God’s sake, Sherlock, I have enough to do without having to worry about you doing something _reckless_ whenever you get upset.”

“Then _don’t!_ If it’s such a bother.” 

“If only it were that simple.” Mycroft murmured carelessly. 

“Get _out_.” Sherlock ordered, voice breaking. 

There was a cursory knock on the door. “Mycroft?”

Mycroft blinked at the sudden light and it took him a moment to bring his mother into focus. Sherlock went completely still and silent.

“My dear, what are you doing here in the dark?” Helena asked curiously. “Everyone downstairs is asking for you. Is that your brother under the duvet?”

“He’s asleep.” Mycroft said quickly. 

“Oh, the poor darling. He tries so very hard to pretend he’s all grown-up but he’s only just a child still.” Helena cooed. “And he misses you terribly, you know.”

“I worry about him.” Mycroft said softly, getting to his feet and stopping for a brief moment to smooth down the ruffled curls on the top of Sherlock’s head. “Constantly.” Then he turned around and gently but firmly ushered his mother out of the room.

Helena smiled at him when he closed the door behind them. “Such a good big brother.”

Mycroft pulled up a weak smile in return. “Kindly let me know if Sherlock gets into any more trouble.”

“My _dear_ ,” Helena tittered, “Sherlock’s _always_ in and out of trouble, you know what he’s like... and I’m sure I don’t know the half of it. But he gets along and so do I. No, I couldn’t bother you unless it were something truly serious.”

“This was rather serious.” he replied vaguely. 

Helena stared at her son with a curious, uncertain expression on her face. “I’m sure I don’t know what you mean. He was just a little indisposed-- must have caught something at school or eaten something that didn’t agree with him. You needn’t fret so.”

Mycroft eyed his mother probingly for a moment, then gave her a stiff smile. “I meant the row with Victor.” he clarified. 

“Oh.” she said with some surprise. “Well. That was certain to happen sooner or later, wasn’t it? To be honest, I’m surprised it lasted as long as it did.” 

“He was never right for Sherlock.” 

“No, I suppose not. Sherlock’s so... singular.” Helena agreed. “But you mustn't use that as an excuse, my dear. Though other people may come and go, family must always stand together, Mycroft.” Helena said firmly, giving him a stern look.

“Of course, Mummy.” he answered dutifully.

“I don’t know if you remember, when Sherlock was a tiny thing and you just a little boy too, and you used to read him all those stories.” she sighed, dabbing at her eyes.

“I hadn’t thought of that in a long time.” Mycroft confessed.

Helena took Mycroft’s hand and squeezed it lightly. “You’ve been so helpful, my dear. I don’t know what I would have done if Sherlock had been my first.

“You’ll keep looking out for him, won’t you, Mycroft?” she asked, gripping his arm as they went down the stairs together. “I do all I can but nothing could have prepared me for... _well_ \-- No, listen, I might not... understand you but you are my sons and I have always loved you to the best of my ability.”

“Mummy--” Mycroft began uncomfortably.

Helena shook her head, lips pressed tight to stop their quivering. “Just promise me.”

“Yes, of course, Mummy.” Mycroft said soothingly. 

Helena beamed at him. 

 **

Sherlock stood in the shower, shivering. His head was bowed and his breathing burst loudly in short, wet gasps. He watched the water draining from the bathtub, barely holding himself upright, his hand slipping on the wet tile. Sherlock clutched at his side and gagged, squeezing his eyes shut when he threw up. 

He stumbled to the living room still wet, rubbing the water and the sting from his eyes. He shrugged into his dressing gown though it stuck to his damp skin and twisted around his chest when he lay on his side. Bringing his knees to his chest he tugged at the robe until it covered him almost to the ankles. 

Sherlock had to use both hands to dial. 

“ _Well_ , this _is_ a surprise.” Mycroft answered after the third dial tone; Sherlock’s thumb slid briefly over the _end call_ button. “What can I do for you, brother dear?”

Sherlock put the phone to his ear and against the armrest so that he wouldn’t have to hold it. 

“Sherlock?”

“Nothing. I was bored.” Sherlock answered after a moment. 

There was a pause. 

“Not an unheard of occurrence.” Mycroft responded. 

“No.” Sherlock rasped.

“But I was under the impression you were keeping busy... _solving crime_ with that detective-- Lestrade, is it?”

“Murder solved. _Case closed._ Everyone go home.”  The words stuck in his throat. 

“Ah.” Mycroft could be heard giving a short command, unintelligible. 

“This ‘consulting detective’ business... It’s not a solution, Mycroft.” he murmured, short of breath.

“It’s better than a seven percent solution.” 

A muscle twitched in Sherlock’s jaw. “How would you know?”

“I have not received a phone call from the hospital in more than five years. I see that as a distinct advantage over the cocaine.”

“It’s not _enough._ ” Sherlock pressed the palm of his hand to the side of his head, squeezing his eyes shut.

“Do I need to call an ambulance, Sherlock?” Mycroft asked abruptly.

Sherlock exhaled noisily. “No.” He brushed away the moisture from his temple before letting his hand drop on the touch, limp. “Don’t be absurd.” he added. 

“Hm.” Mycroft replied. “I’ve been thinking--” 

Sherlock made a small scoffing sound. 

“--it may be beneficial for you to find a flatmate.”

He wrinkled his nose. “No.” 

“We _will_ talk about this.” Mycroft said unperturbed. 

“Not if I can help it.” Closing his eyes, he brought his knees in tighter against his body. “I don’t want to talk to you anymore. I’m going to hang up now.”

There was no answer. 

“Mycroft?”

“I’m here, Sherlock.” Mycroft said.

Sherlock frowned when he heard the sound of a car door being closed. “ _Don’t._ Don’t come over.”

Mycroft clicked his tongue. “I’m already on my way.”

“Well. Turn around.” Sherlock demanded. 

“Too late now.” he replied placidly. 

Sherlock lay on his back holding the phone in a loose grip against his chest. Quick, stuttering breath in. Tremulous breath out. He put the phone to his ear again. “Bring breakfast.”

“It’s four in the morning.” Mycroft complained. 

“It’s non-negotiable.” Sherlock eyed the blanket thrown over the armchair but made no move to get it. “If I have to suffer your presence--” 

Mycroft cut him off. “I’ll see what I can do.”

He clutched the dressing gown tight around him in an abrupt movement. “Don’t take long.” 

“I’m hungry.” Sherlock clarified before his brother could reply.

Mycroft sighed. “I know.” 

 **

“Bullet holes in the wall. That can be funny. But this--” John used his arm to encompass Sherlock and the gun on the coffee table. “ _This._ This isn’t funny at all, Sherlock.”

Sherlock was seated on his chair with his arms around his knees and his head tilted toward the window, away from John.

John gave a violent nod at the sound of footsteps on the stairs.

“I told you _not_ to call him.” Sherlock said without looking at John.

“Yeah, well, I did.” John leaned forward as Mycroft appeared in the doorway; he looked from John to Sherlock to the gun on the table then tapped his umbrella on the floor. 

John slapped a hand on his knee and turned to face Mycroft with a grim smile on his face. “The gun was loaded.” He pointed at Sherlock with his hand closed in a fist. “The gun was loaded.” he repeated with a short, bitter laugh. 

Mycroft’s expression of polite but dispassionate attentiveness did not change. “The gun was loaded, but was the safety on?”

John narrowed his eyes for an instant, his mouth a little agape. “Right.” He smoothed a palm over his thigh and got his feet. “I need some air. Will you stay with him?”

“I don’t need a babysitter.” Sherlock groused.

“No. _Shut up_.” John’s chest heaved. “I need to know your brain isn’t going to be _decorating the wall_ when I get back.”

“I’ll stay.” Mycroft said. 

John nodded. “Good. I’ll be... back.” He caught Sherlock’s furtive glance and stared back at him unflinchingly. “And I’m taking these.” he added, opening his fist to reveal the glint of the bullets cupped in his palm. 

When Sherlock rolled his eyes, the shadows in the corners of John’s mouth deepened. He paused at the door, struggling into his jacket, then went out with another nod and a tight grin. 

Mycroft gave his umbrella a twirl. “Well.” 

“What?” Sherlock bit out. He jumped up from his seat only to turn in place and throw himself back down in his chair. “John’s an idiot. He misread the situation in every possible way.”

“That’s impressive.” Mycroft commented. “ _Do_ tell me more.”

Sherlock’s mouth tightened in a downward curve. “If you _must_ stay, need you talk as well?”

Mycroft shrugged and sat down on the couch, leaning back and resting his chin on his hand as he watched his brother in silence. 

Sherlock drummed his fingers on the armrests of his chair and knocked his bare feet together and against the floor. The carpet deadened the sound. “ _Shut up_.” he snapped at last.

Mycroft blinked at him innocently. “I didn’t say anything.”

Sherlock glared at him and kicked him out of balance when he tried to cross his legs. 

“It won’t change anything.” Sherlock said, looking quickly at the gun before turning back to his brother. “He’ll walk around with the bullets in his pocket for a few weeks and that will be all.”

“If you say so.” 

“John is exceptionally resilient to eccentricity.” Sherlock argued, casting a sullen glance at his brother. 

“Perhaps.” Mycroft replied. “I think you underestimate his _concern_ for you, however.”

Sherlock waved a hand dismissively. “He’s a doctor. He _cares_ about people.”

Mycroft stared at his brother with a curious expression on his face. The movement of his head from side to side was almost imperceptible. He wrapped his hand around the handle of his umbrella in a white-knuckled grip. “This is dangerous.”

Sherlock frowned. “Of course it’s dangerous.The adrenaline rush associated with my lifestyle is what keeps him here.”

“You believe John Watson... is an addict.” 

“You _know_ this.”

Mycroft made a noncommittal sound. “In that case, what have you to fear?” he asked. “It’s unlikely he will be able to find a better ‘fix’ than the one _you_ can offer him.”

“I’m not afraid.” Sherlock countered, voice sharp. 

“Or is it the possibility of rehabilitation that scares you?”

The carpet snagged on the table as Sherlock tried to push it away with his feet. An empty cup of tea that had been on the edge toppled over onto the floor but didn’t break. “He’ll leave eventually. _I know that_ , Mycroft. And I’ll be _fine_.”

Mycroft eyed the cup on the floor. “I’m certain of it.” He nudged it toward him with the tip of his umbrella and bent down to pick it up. “Which is why I don’t quite understand the need for all _this._ He’s still here, after all.”

“There is no _this._ ” Sherlock interjected.

Mycroft turned the cup over in his hands instead of setting it back on the table. It had a chip on the lip. “And so cruel, Sherlock. His own gun. It would devastate him.” 

Sherlock went still. His face was blank when Mycroft lifted his eyes from the cup to look at him. “But you wouldn’t do that, would you? Not to John Watson, at least.” 

“No.” Sherlock swallowed, mouth dry. He took the cup from Mycroft and set it upright on the table, next to the gun. “I wouldn’t do that to John.”

Mycroft smiled slightly. “No, I don’t think you would.”

 

* * *

 

_Because brothers don’t let each other wander in the dark alone._

Jolene Perry

 

**Author's Note:**

>  A continuation of sorts-- though it can be read as a stand-alone-- to 'Square Pegs' (http://thedeathchamber.livejournal.com/13982.html).


End file.
